The present disclosure relates generally to a pneumatic drive line having a non-uniform internal cross-section that is used to drive pneumatic surgical instruments in surgical procedures such as, for example, a vitrectomy procedure.
A vitrectomy procedure may be performed to clear blood and debris from the eye, to remove scar tissue, or to alleviate traction on the retina. Blood, inflammatory cells, debris, and scar tissue may obscure light as it passes through the eye to the retina, resulting in blurred vision. The vitreous may also be removed if it is pulling or tugging the retina from its normal position. Some of the most common eye conditions that require vitrectomy include complications from diabetic retinopathy such as retinal detachment or bleeding, macular hole, retinal detachment, pre-retinal membrane fibrosis, bleeding inside the eye (vitreous hemorrhage), injury or infection, and certain problems related to previous eye surgery.
In a vitrectomy, the surgeon may create three tiny incisions in the eye for three separate instruments. These incisions may be placed in the pars plana of the eye, which is located just behind the iris but in front of the retina. The instruments which pass through these incisions may include a light pipe, an infusion port, and the vitrectomy cutting device. The light pipe is the equivalent of a microscopic high-intensity flashlight for use within the eye. The infusion port may be used to replace fluid in the eye and maintain proper pressure within the eye. The vitrectomy probe, or cutting device, may work like a tiny guillotine, with an oscillating microscopic cutter to remove the vitreous gel in a controlled fashion. This may prevent significant traction on the retina during the removal of the vitreous humor.
Traditionally, the vitrectomy probe is connected to a surgical machine that is used to perform the vitrectomy procedure and other surgeries on the posterior of the eye. The surgical machine may provide power to and control the operation of the attached vitrectomy probe. In order to provide pneumatic power to the vitrectomy probe, the surgical machine may include a pneumatic or air distribution module. This pneumatic module may condition and supply compressed air or gas to power the probe. The pneumatic module may be connected to a cylinder that contains compressed gas.
Typically, the surgical machine connects to a vitrectomy probe via a tubing. Such tubing traditionally has a constant inside diameter along the length of the tubing. Thus, the size of the passageway within the tubing remains the same as the pressurized gas travels from the surgical machine to the vitrectomy probe. This results in a tube having the same degree of flexibility throughout the length of the tube. Additionally, because the tubing has a constant inside diameter along the length of the tubing, the tubing is not optimized for pneumatic performance.